With the preseason schedule 75 percent done, the Boston Celtics stand at 1-5. And the one victory came on a night the New York Knicks decided to sit just about everybody.

One could point to Boston's point differential (+5) as evidence the Celtics have played better than their record, but the stat is misleading -- sure, Boston could have won two or three extra games, but some of the close losses featured unexpected comebacks against another team's second or third unit. Chris Babb, Courtney Lee, MarShon Brooks -- all have led late rallies for the Celtics to turn otherwise bleh outings into thrilling finishes.

Since Stevens obviously spent time tinkering with his lineups, we could perhaps dismiss the first few defeats, or at least put an asterisk next to them: *the starting lineup was little more than an experiment. We could also note that Gerald Wallace has missed two and a half games already for scheduled rest, and his absence has been felt. But still, the 1-5 record is pretty reflective of what Boston has been. If the Knicks had not decided to turn Ike Diogu into a go-to guy for a night, it's possible head coach Brad Stevens would still be searching for his first preseason victory.

Stevens has paced his team so far. He has juggled lineups and tried to learn more about his players, not just what they can do as individuals but how they operate together. Of course, the coach watched plenty of game film and devoured past statistics to learn more about his roster coming into the season. But with no stars on the roster and plenty of parity at several positions, training camp and preseason has essentially served as a tryout period. Players have all indicated they can feel a clean slate; perhaps that's best illustrated by Jordan Crawford's emergence as a probable starter and occasional point guard.

Stevens still seems to have full support in the locker room, but at least until Rajon Rondo returns from injury, it's more obvious now that this could be a difficult season. Some relatively well-known names on the roster (like Jeff Green, Avery Bradley and Jared Sullinger) might have obscured the fact for some that this team has glaring issues. Through six exhibition games we have learned a lot about the Celtics, and not all of it has provided optimism.

I would ask whether you want the good news or bad news first, but I'm the dictator here (and/or I don't know how you would ever respond to me), so we'll start with a negative.

Interior defense

Even once Rondo comes back, some big issues could haunt the team all season. Knowing his team doesn't have a natural defensive anchor, Stevens has tried to preach the concept of stopping teams as a full unit. But the lack of an interior presence has been glaring throughout the preseason. Clearly, as expected, the Celtics miss Kevin Garnett. Watching them try holding off opposing frontcourts despite a lack of both length and athleticism inside, Garnett and former coach Doc Rivers look all the more impressive for turning last year's Celtics into an elite defense.

As Kris Humphries noted following the loss to Brooklyn, this year's Celtics are trying to compensate by "over-helping." Stevens has noted several times how he wants guards to chip in on the glass, and that will assist some. But ultimately, the NBA's best defenses almost all have big men who can snuff out the pick and roll and limit interior success. Boston doesn't really have that. Sullinger's an underrated defender who generally works angles well, but he's not explosive enough to act as a real impediment to opponents inside. Brandon Bass is quicker on the perimeter and tough to beat in a one-on-one setting, but he doesn't have enough timing or height to be a top-notch help-side defender. Kelly Olynyk, Humphries and Vitor Faverani all have their issues too, so Stevens is tasked with trying to hide many flaws. No frontcourt combination provides an obvious answer to Boston's interior woes.

By learning how to operate on a string, the defense can improve and perhaps overachieve. But regardless of how impressively Stevens schemes, there's a probability that natural limitations will hold this team back. In Avery Bradley and Gerald Wallace, the Celtics have two highly capable perimeter defenders who should see a lot of minutes. But behind them, Boston really doesn't have much resistance.

The frontcourt hasn't been all bad, though.

Young big men impressing

During media day, when Sullinger called himself "not close" to proper basketball shape, I figured he would struggle at least to begin the preseason. Instead, wearing an extra layer of blubber, he's playing like Boston's best healthy player, a great sign for the 21-year old coming off season-ending back surgery.

Also succeeding despite athletic limitations: Olynyk, who has essentially become Sullinger's white, long-haired twin brother. Possessing different skill sets, both nonetheless help because of the same reasons: intellect, savvy and a deep toolbox of basketball ability. The duo has yet to hit its outside stride (Stevens wants both to keep firing away from the 3-point arc), but has shown nice high-low chemistry. In limited defensive reps against perimeter players, normally of second-unit caliber, Olynyk has also revealed a decent ability to move his feet. If he can continue to stay in front of wings, including starters, the Celtics could combat small units with a Sullinger-Olynyk duo -- allowing Olynyk to take advantage of his height and low-post touch, like he did while punishing the Raptors for 11 first-half points Wednesday night. I'm not sure the Celtics can use that duo against all small lineups, but it could provide for interesting advantages in certain situations.

Like I mentioned earlier, Olynyk and Sullinger (like all the other Celtics big men) are not perfectly equipped to protect the rim. But the Celtics have often looked their best this preseason with those two in the lineup, when passing becomes contagious and lanes to the hoop suddenly open a little wider.

Keep in mind: Though Stevens will try his best to manufacture wins, this season is as much about cultivating assets and finding out exactly what the roster holds. If Sullinger and Olynyk can continue revealing their potential, that bodes well for the future regardless of how many games Boston loses.

The obligatory Jeff Green discussion

Though Green hasn't shot the ball well, I'm convinced his outside touch will come around. He's attempting mostly good looks and has started to make more of them in the past couple of games. Over larger sample sizes, shooting averages tend to regress to the mean.

But we should note other, more troubling aspects of Green's preseason start, which should not be viewed as unexpected. Even when Green emerged last year, he did so by becoming a consistently efficient scorer, not by boosting production significantly in other areas. He remains a bad rebounder for his size and position; and despite defensive improvements, he has not turned himself into a plus on that end of the court. After an offseason of putting pressure on himself to become the guy, it appears Green has not boosted the worst aspects of his game. Use your best Dennis Green voice and say it with me: He is who we thought he was.

Green was still good last season, though. And the Celtics could really use him to play more like he did then. Teams can afford to pay very little attention to Bradley and Wallace on the perimeter, and none of Boston's other outside options elicit much fear in opponents, either. Green reverting back to offensive form would help to alleviate pressure off of everyone else, and would benefit the team both in the short- and long-term. (Read: Dear Jeff, Please don't throw away all the trade value you built last season. Sincerely, Danny Ainge)

Prognostication

Once games start to matter, the Celtics will benefit in some obvious ways. Stevens is more comfortable with his roster, Wallace won't sit out just because, and Boston will begin using its best players and combinations more often. While other teams will also give heavier workloads to their most talented players, the Celtics should considerably more cohesive once Sullinger, Wallace and a few other guys play more minutes.

But the first three-quarters of preseason appears to have validated all the worst fears about this team. When Stevens looks down at his bench, he'll see a lot of players who could contribute to playoff rotations -- but he'll also see a strange mix of decent players who don't really match in obvious ways. Making matters worse, Boston's November schedule looks more dangerous than Windsor Horne Lockwood III, the fictional Harlan Coben character known to mutilate humans with his bare hands. The Celtics have six back-to-backs in the first full month, including second legs in Memphis, Miami and San Antonio. By the time Rondo returns from injury, making the playoffs could appear almost impossible.

But if you do indeed watch this team struggle to find itself early, remember it's not all bad. This season has always been more about progress than success, a fact we should all keep in mind.